technical counselor The Spring Warm-Up

in a low-stress environment prior to starting the aircraft engine. Ideally, you will pull the engine through two strokes of each cylinder to assure the engine has ...
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technical counselor The Spring Warm-Up Returning your aircraft to flying status following winter layup GEORGE R. WILHELMSEN, EA A 442664

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pring—and the return of aircraft to the air—is just around the corner, as cold as it may still be in your area. Before you venture back into the skies after your aircraft’s prolonged winter layup, there are actions you should take to make sure your plane is ready. Failing to take these steps can result in simple glitches in the way your plane flies or challenges to its ability to start and run properly. These tips apply to just about any aircraft that has not been flown on a routine basis during the cold winter months. Some problems are specific to the type of fuel used, but for the most part, these tips can help anyone get an airplane back to flying status. If you are the owner of a certificated aircraft, some of this work will need to be performed by a trained professional, while other portions of the work can be completed by the owner as defined in Federal Aviation Regulations Part 43.

Step 1: De-Winterize Did you winterize with desiccant spark plug replacements? If so, remove the desiccant spark plugs, and if still acceptable based on color, cap and replace them in their container for use next winter. If the desiccant plugs are worn out, or if the manufacturer provides just single-season usage, dispose of them properly. If you were aggressive in engine corrosion protection and sprayed the inside of your engine cylinders with preservative oil, follow the engine manufacturer’s instructions for removal. This usually includes removal of the spark plugs and flushing with a solvent to dissolve the preservative oil so it can be removed from the cylinders. Since the spark plugs are out of the engine, pull the engine slowly through several revolutions of the propeller. This will help to make sure that all bearing surfaces are wetted 88

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in a low-stress environment prior to starting the aircraft engine. Ideally, you will pull the engine through two strokes of each cylinder to assure the engine has been properly prepped. As long as you have the plugs out, make sure the gaps are properly set. Reinstall the spark plugs; follow the recommended rotation pattern (to even out the wear on the electrodes) and the installation torque requirements.

If rodents made a winter home in your fuselage, you will need to look carefully at your wiring harness.

If your aircraft went into storage needing an oil change, take this opportunity to drain the oil and check the oil screen or replace the oil filter. Your engine will tend to breathe during heating and cooling cycles and can pick up moisture. By draining the oil, you can flush out this corrosive water before it can have an impact on your engine. Ideally, the engine oil should be changed before the aircraft goes out of action for the winter. This is because the combustion process deposits moisture and corrosive compounds in the oil during flight. Over time, these deposits can build up in your engine oil to high levels. Removing those products from the engine and replacing it with fresh oil will help protect your engine better than laying it up with used oil. If you attached any desiccant to the exhaust pipes and aircraft intake ports, or if you have installed any plugs to keep out varmints and moisture, this is also the time to remove these devices. While in the engine compartment, this would be a good time to reinstall the battery if previously removed. Whether reinstalling or servicing the existing battery, it is a good time

Step 3: Perform an Airframe Preflight

Telltale signs of mice in your plane include chewed up towels and interiors. That’s a sign a more detailed inspection is necessary.

to check the acid level in the battery cells, and to service the cells with demineralized water if it’s low. Have the battery charged up with an approved battery charger to make sure it will be ready for you to start the plane. Some pilots might wonder why they need to use demineralized or de-ionized water. Depending on where you live, tap water can contain everything from zinc to chlorine calcium carbonate to iron, and just about any other element. These impurities can plate out on your battery cell walls, resulting in shortened life. To get the best life out of your battery, use only de-mineralized or de-ionized water.

You will need to perform a thorough airframe preflight. To facilitate this inspection, you will need a strong flashlight and inspection mirror. To begin, perform your normal airframe preflight. This typically checks the big-ticket items, such as flight controls, tires, and pitot tube, and if covers are installed and the static port is unplugged. Next, do the same preflight, but this time focus on checking any openings in your airframe. You are specifically looking for nesting materials as well as signs of mud dauber nests. Any nesting materials need to be removed. If your plane is equipped with retractable landing gear, perform a thorough inspection of the gear bays, looking for signs of nesting or damage. If your plane has an up-lock mechanism, inspect it for condition and signs of damage. Finally, if your gear has not been lubricated as recommended by the original equipment manufacturer or kit designer, properly lubricate your landing gear. This is also a good time to cycle your flaps, to make sure they reach full extension and are not binding either in the up or down direction. As long as you are outside your plane, this would be a good time to give it a good cleaning—if the weather is warm

Step 2: Perform a Cockpit Preflight The cockpit also needs to be closely examined as the aircraft is coming out of winter storage. Signs of rodent nesting include tattered fabric or paper towels. If you find something that looks like it has been chewed on, you’ll need to start taking things apart to find the nest. Rodents leave waste products in their nests, and when exposed to moisture, these waste products can become corrosive, damaging aircraft components. If rodents made a winter home in your fuselage, you will need to look carefully at your wiring harness. While it is rare, mice have been known to gnaw on wires, and if insulation has been removed between two wires, a short can develop. Use a strong flashlight and inspection mirror for best results. Once you have this inspection behind you, check the seats, seat rails, and instruments in the control panel. Look for the unexpected, such as moisture in the artificial horizon or readings that do not make sense. If you find any problems, maintenance will need to be performed to correct the problems you identified. Remove your control lock if installed, and slowly move your flight controls through their full range of motion. As you move the control wheel or stick, listen for any telltale sounds indicating interference such as scraping or squealing. If such sounds are heard, or if resistance is felt in the flight controls, this is a sign that an internal inspection is warranted to isolate and correct the problem. Finally, with the battery reinstalled in your plane, power up the panel and make sure everything works as you expect it to. If your plane is set up for night flight, this is a good time to check the interior and exterior lighting. Also check any cabin flood lighting, which tends to get missed on these checks because they are generally done in daylight.

Looking into the unprotected engine compartment of this plane, you can see evidence that birds have set up housekeeping.

Be sure to service your battery with demineralized or distilled water to get the maximum service life. EAA Sport Aviation

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technical counselor enough. Use the appropriate cleanser for your paint, and gently clean away dirt and grime. Use the proper cloth and cleaners for your windshields, and remove bugs and dirt from the windows to assure you will be able to effectively see and avoid other traffic.

Step 4: Check Your Logbooks Before you jump into the plane, this is a good time to check your aircraft’s logbooks. If you have an emergency locator transmitter on board, check to make sure the battery is still within the installation time limit. If you fly in controlled airspace, check to make sure your altimeter/encoder static check is within the required inspection frequency. Check to see when your annual was last performed and when it is due, and if not checked previously, when your oil was last changed and when it is due to be changed. Be sure to correct any problems you identify in this logbook review process.

Step 5: Start the Engine Now that the preflight is ostensibly complete, it’s time to start the engine. Follow your usual prop-clearing activities and then engage the starter. Check to see that the engine starts and that oil pressure rises as you expect. After the oil temperature reaches the proper temperature, move the aircraft to a safe area and perform an engine run-up to check the magnetos and variable pitch propeller, if applicable. Any anomalies identified in the enginestarting process should be noted, followed by engine shutdown for prompt investigation and correction. Once any glitches in the inspection have been addressed you will be ready to fly. Better yet, your airplane will be in better condition, ready to serve your flying needs with fewer challenges and surprises, which is what the non-flying public, and your passengers, expect.

George Wilhelmsen holds a commercial certificate (airplane single-engine land) with an instrument rating and has more than 1,000 hours of flight experience. He has a bachelor’s degree in engineering technology with a background in DC, analog, and digital controls. He flies a Beech Debonair. 90

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